Van Allen Radiation Belt

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Van Allen radiation belt is a torus of energetic charged particles (plasma) around Earth, which is held in place by Earth's magnetic field. This field is not uniformly distributed around the Earth. On the sunward side, it is compressed because of the solar wind, while on the other side it is elongated to around three earth radii. This creates a cavity called the Chapman Ferraro Cavity, in which the Van Allen radiation belt resides. It is split into two distinct belts, with energetic electrons forming the outer belt and a combination of protons and electrons creating the inner belt. In addition, the belts contain lesser amounts of other nuclei, such as alpha particles. The Van Allen belts are closely related to the polar aurora where particles strike the upper atmosphere and fluoresce.